Wireless Set No. 52 Canadian - Project

[David Dunlop]

Once I had removed the COVERS, Metal, No. C1 from its retaining brackets on the rear of the Carriers No. 4, things suddenly started to make much more sense in the Instruction Manual for the 52-Set. In particular, Section 6.11 starting on Page 137. This section explains the correct procedure for reinstalling the Receiver, Supply Unit and Sender into the Carriers No. 4, if all three have had to be removed at the same time for any reason.

The only thing that holds the PLUG, Assemblies, Multi to the 52-Set are the five individual Bakelite plugs themselves, once they are pressed into the five corresponding sockets fitted to the back of the three set components. If none of the three components are present, the PLUG, Assemblies, Multi becomes a free-floating object inside the Covers, Metal, No. C1. As a unit, this PLUG, Assemblies is heavy and the vertical wiggle room within the Covers is not enough to prevent the Plug and component sockets from lining up with each other. Same for the lateral movement to either side of the set. With the Cover screwed in place, the two Cover Retaining Brackets either side minimize the side-to-side wiggle of the Plus Assembly to acceptable limits. The exception is the depth of the Covers. See the first photo.

The internal depth of the Covers, Metal, No. C1 is twice that of the Plug Assemblies, Multi. If all three set components have been removed from the Carriers at the same time, as soon as you attempt to replace the first component, it will simply push the Plug, Assemblies, Multi to the back of its Covers, out of reach. You will have no choice at that point, other than to read up on Section 6.11 of the Manual and perform a ‘by the book’ reinstall.

I would also strongly advise you carefully clean the connecting surfaces of both the Bakelite plugs and sockets on the 52-Set. They are a snug fit to start with and it will not take much in the way of fine dirt or dust building up on the surfaces to cause them to bind against each other when being connected or disconnected. They are all black Bakelite and all of mine looked fine at first, but it is amazing how dirty a damp cloth and toothbrush gets when you start cleaning.

It is also a good idea when connecting, or disconnecting these Bakelite connectors, to apply the force you are using perpendicular to the faces of the connectors. In other words, push straight in and pull straight out. If the force you are applying gets too far off the perpendicular, the connecting faces of the plugs and sockets will bind against each other. Bakelite was never a forgiving material at the best of times and these parts are additionally, now 75+ years old. Be nice. The last picture posted here shows the damage that can happen to the Plugs if not treated carefully. Four out of the five in my Carriers No. 4 have this type of damage present.

The nice find was that the paper terminal labels inside the five plugs are minty originals.

The other photo I posted is of the back of the Plug, Assemblies, Multi. Again, a one piece sheet steel stamping, satin nickel plated. The metal gauge seems to be the same as used for the Covers and Carriers.

I have been thinking about the design of the Plug, Assemblies, Multi when it comes to all three components of the wireless set being removed from the Carriers. I have not yet seen any documentation from Canadian Marconi, or the Military end users of the 52-Set flagging this topic as an issue or problem. No revised Covers. No apparent modifications. The logic of the design may be difficult to grasp today, but it would seem to have been a valid design. The same style of connectors system was used by Marconi on wireless sets built for use by the Navy during the war and no concerns appear at that end either.

Two possible justifications for the design come to mind. When mounted on the back of the Carriers No. 4, the Plug Assemblies are open to the inner case of the Carriers. When the fans in the Supply Unit and Sender were operating, warm air would certainly be capable of circulation around the Plug Assemblies so they would stay dry. Secondly, as mentioned earlier, Bakelite is not the most forgiving substance. If the Covers were snugged up against the Plug Assemblies firmly, it is possible the shock of any blow to the surface of the Covers could transfer to the Bakelite connectors and crack them.

That’s all I’ve got on this topic at the moment.

David

[David Dunlop]

Well, it was an interesting and productive day today.

Debbie and I got the Carriers No. 4 up onto its intended resting place on the wireless bench to start with. I then took the opportunity, while the Plug Assemblies was out in the open to check the continuity of all the circuits therein. They checked out just fine. Then the individual plugs got a cleaning.

Finally, I slid the three main set components into the Carriers No. 4 and reconnected the Plug Assemblies and Cover. That is one challenging task, and I much more fully appreciate Marconi's warnings in the manual about such work, having now gone through it. It did not help that the lower bank of screws on the Cover had to be reinstalled blind because there was only seven inches of clearance between the back of the Carriers No. 4 and the basement wall. Not thrilled about eventually having to do it again when it comes time to repaint the Carriers No. 4, but at least I now know more fully what to expect.

The attached photo shows the 52-Set in its place of honour on the bench. The set from Montreal did not have the Coil, Aerial Tuning assembly with it, so I wonder when the last time was that this set actually had one fitted to the top of it?

Hard to believe I am now just two small connector cables away from having a fully integrated 52-Set. I don't think the progress on this project has fully sunk in yet!

David

[David Dunlop]

This part of the project is a ‘Planning Ahead’ segment, more than anything.

I will eventually be doing a restoration of the Supply Unit for my 52-Set, which is going to bring the two dynamotors into the picture. The main concerns with them will be the inspection and cleaning of the brushes and armatures, which is a relatively straightforward process. Where it will get interesting, however, is the cleaning and regreasing of the bearings.

This 52-Set was very likely last operated sometime in the 1970’s, and when the dynamotor bearings were last cleaned and lubricated prior to that is anyone’s guess.

Version 2 of the Parts Listings for the 52-Set, issued July 1948, identifies the grease used as GREASE, Lubricating, Andoc and it was available in 1-pound tins.

In 1954, Modification Order No. 4 was issued dealing with changing the original grease to one identified as 3-GP-683a, which was an Arctic tolerant grease, if the 52-Sets were being deployed there.

While checking the web today, it appears Andoc grease was an Exxon Product and version ‘Andoc C’ was discontinued in 2001. I have no idea what the qualities of this particular grease were, to be able to match it to a modern substitute, so I am very much open to suggestions for an appropriate substitute. I would like to track down suitable grease ahead of time, rather than have the project grind to a halt, when it reaches the point of restoring the Supply Unit.

David

[Chris Suslowicz]

Originally Posted by David Dunlop

This part of the project is a ‘Planning Ahead’ segment, more than anything.

I will eventually be doing a restoration of the Supply Unit for my 52-Set, which is going to bring the two dynamotors into the picture. The main concerns with them will be the inspection and cleaning of the brushes and armatures, which is a relatively straightforward process. Where it will get interesting, however, is the cleaning and regreasing of the bearings.

This 52-Set was very likely last operated sometime in the 1970’s, and when the dynamotor bearings were last cleaned and lubricated prior to that is anyone’s guess.

Version 2 of the Parts Listings for the 52-Set, issued July 1948, identifies the grease used as GREASE, Lubricating, Andoc and it was available in 1-pound tins.

In 1954, Modification Order No. 4 was issued dealing with changing the original grease to one identified as 3-GP-683a, which was an Arctic tolerant grease, if the 52-Sets were being deployed there.

While checking the web today, it appears Andoc grease was an Exxon Product and version ‘Andoc C’ was discontinued in 2001. I have no idea what the qualities of this particular grease were, to be able to match it to a modern substitute, so I am very much open to suggestions for an appropriate substitute. I would like to track down suitable grease ahead of time, rather than have the project grind to a halt, when it reaches the point of restoring the Supply Unit.

David

Searching for Andoc C Grease in Google, got me a "Table 14a List of Consumable Material" and Item 55 is "Grease, ball and roller bearing" Specification "Commercial, Standard Oil ANDOC C" in 8oz. tubes, FSC 9G9150-261-8311, intended use "Lubricating bearings for high speed and temperature", which sounds about right.

https://www.nationalprecision.com/mi...lubricants.php suggests "Polyrex EM" as a replacement for Andoc C, though it looks like Beacon 325 or Royco 27 might be good substitutes depending on temperature range.

The last two are Lithium grease variants, and with any change of lubricant type it's very important to get rid of any existing grease before re-filling the bearing (to avoid chemical reactions between different grease types that can -under some circumstances- produce a compound of abrasive rather than lubricating properties).

I think these are aerospace/military lubricants and therefore Not Cheap. Any standard grease for small motor bearings should be fine.

(I made the mistake of looking up Royco 27 on Amazon and the first hit was "Royco Mchuzi Mix (Spicy Beef Flavour)" which to my mind has dubious lubricating properties and is unlikely to be suitable for this application.)

Chris.

[David Dunlop]

I have not reported much on this project recently, so thought an explanation would be in order. I have been sidetracked with a related project(s).

I am at a point now where I need to go through both receivers to align and calibrate them. This requires a multimeter and an oscilloscope. I have a good analog and digital pair of meters to do part of the work with, and I had a working OS8-B Oscilloscope until last October, when a pair of electrolytic can capacitors in the power supply died. Exact modern replacements are available but pricy.

In November, a local friend told me of a pile of surplus electronics that had just been dropped off at a local museum and that most of it was not usable for the museum and headed for scrap. He suggested I drop by for a rummage. Ended up coming home with four semi scrapped Tektronix oscilloscopes and a pile of related goodies. The scopes weighed 65 pounds each and it took two car trips to get all the stuff home. All for the price of a large Timmies Coffee.

Out of the four scopes, I now have one restored and finally doing almost all it is supposed to do. Still a bit of fine tuning to sort out, but the end of this project is finally in sight. Then I can get back to the two 52-Set receivers and get them finished.

David

[David Dunlop]

Thanks for the information on the grease, Chris. You are right...best not mix it up with the spices.


David

[David Dunlop]

I had to take a break from oscilloscope work this week as my head was starting to spin, and I think I was also developing a mild case of 52-Set Withdrawal.

I decided to try a little more hand polishing to remove more of the yellowed varnish top coat on the Sender panel. A simple half hour of freehand work without work lights. I tackled the lower right quadrant of the sender fan door assembly, where I had earlier removed a set of red numbers. (See Posts 201 and 228).

The polish cloth was coming away with quite a brown tone to it as I worked, but the colour did lighten up quite a bit and when the time comes to clean the Sender panel, I think I should be able to get a very close match to the upper portion of the Receiver panel.

The other little bit of excitement was the arrival yesterday of a second Cases, Spares Box for the 52-Set.The interior KimPaK lining in this one is as close to mint as one could hope for, compared to my other box. (See last photo Post 168). Restoring/replacing that lining was going to be a major challenge, so I was pleased to cross paths with this one.

This box also underwent a NATO conversion on the outside and I will be surprised if any original stencil markings show up. But I will take a careful look...just in case. The exterior of the box was sanded and NATO Greened, and then a large patch of tan paint was slapped on and NATO stencil ID's added in black. It looked so garish, the previous owner toned it down with a uniform coat of green paint.

David